Biological, psychological, and engineering studies on auditory communication and its disorders include: (1) auditory evoked cortical potentials and application to early audiometry, (2) electrophysiological, biochemical and anatomical studies on normal and noise-exposed animals, (3) behavioral studies of auditory function of normal and noise-exposed animals, (4) auditory perception of complex acoustic patterns, (5) perceptual characteristics of deaf children and hearing-impaired adults, (6) development of digital systems for sound measurements, analysis and synthesis of speech, and generation of a variety of sound patterns.